Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux-block into for-3.18

This is to receive 0a30288da1ae ("blk-mq, percpu_ref: implement a
kludge for SCSI blk-mq stall during probe") which implements
__percpu_ref_kill_expedited() to work around SCSI blk-mq stall.  The
commit reverted and patches to implement proper fix will be added.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Kent Overstreet <kmo@daterainc.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Christoph Hellwig <hch@lst.de>

1 files changed, 68 insertions, 9 deletions

diff --git a/arch/xtensa/mm/cache.c b/arch/xtensa/mm/cache.c
index 63cbb867dadd..d75aa1476da7 100644
--- a/arch/xtensa/mm/cache.c
+++ b/arch/xtensa/mm/cache.c
@@ -59,9 +59,68 @@
  *
  */
 
-#if (DCACHE_WAY_SIZE > PAGE_SIZE) && defined(CONFIG_HIGHMEM)
-#error "HIGHMEM is not supported on cores with aliasing cache."
-#endif
+#if (DCACHE_WAY_SIZE > PAGE_SIZE)
+static inline void kmap_invalidate_coherent(struct page *page,
+					    unsigned long vaddr)
+{
+	if (!DCACHE_ALIAS_EQ(page_to_phys(page), vaddr)) {
+		unsigned long kvaddr;
+
+		if (!PageHighMem(page)) {
+			kvaddr = (unsigned long)page_to_virt(page);
+
+			__invalidate_dcache_page(kvaddr);
+		} else {
+			kvaddr = TLBTEMP_BASE_1 +
+				(page_to_phys(page) & DCACHE_ALIAS_MASK);
+
+			__invalidate_dcache_page_alias(kvaddr,
+						       page_to_phys(page));
+		}
+	}
+}
+
+static inline void *coherent_kvaddr(struct page *page, unsigned long base,
+				    unsigned long vaddr, unsigned long *paddr)
+{
+	if (PageHighMem(page) || !DCACHE_ALIAS_EQ(page_to_phys(page), vaddr)) {
+		*paddr = page_to_phys(page);
+		return (void *)(base + (vaddr & DCACHE_ALIAS_MASK));
+	} else {
+		*paddr = 0;
+		return page_to_virt(page);
+	}
+}
+
+void clear_user_highpage(struct page *page, unsigned long vaddr)
+{
+	unsigned long paddr;
+	void *kvaddr = coherent_kvaddr(page, TLBTEMP_BASE_1, vaddr, &paddr);
+
+	pagefault_disable();
+	kmap_invalidate_coherent(page, vaddr);
+	set_bit(PG_arch_1, &page->flags);
+	clear_page_alias(kvaddr, paddr);
+	pagefault_enable();
+}
+
+void copy_user_highpage(struct page *dst, struct page *src,
+			unsigned long vaddr, struct vm_area_struct *vma)
+{
+	unsigned long dst_paddr, src_paddr;
+	void *dst_vaddr = coherent_kvaddr(dst, TLBTEMP_BASE_1, vaddr,
+					  &dst_paddr);
+	void *src_vaddr = coherent_kvaddr(src, TLBTEMP_BASE_2, vaddr,
+					  &src_paddr);
+
+	pagefault_disable();
+	kmap_invalidate_coherent(dst, vaddr);
+	set_bit(PG_arch_1, &dst->flags);
+	copy_page_alias(dst_vaddr, src_vaddr, dst_paddr, src_paddr);
+	pagefault_enable();
+}
+
+#endif /* DCACHE_WAY_SIZE > PAGE_SIZE */
 
 #if (DCACHE_WAY_SIZE > PAGE_SIZE) && XCHAL_DCACHE_IS_WRITEBACK
 
@@ -103,7 +162,8 @@ void flush_dcache_page(struct page *page)
 		if (!alias && !mapping)
 			return;
 
-		__flush_invalidate_dcache_page((long)page_address(page));
+		virt = TLBTEMP_BASE_1 + (phys & DCACHE_ALIAS_MASK);
+		__flush_invalidate_dcache_page_alias(virt, phys);
 
 		virt = TLBTEMP_BASE_1 + (temp & DCACHE_ALIAS_MASK);
 
@@ -168,13 +228,12 @@ update_mmu_cache(struct vm_area_struct * vma, unsigned long addr, pte_t *ptep)
 #if (DCACHE_WAY_SIZE > PAGE_SIZE) && XCHAL_DCACHE_IS_WRITEBACK
 
 	if (!PageReserved(page) && test_bit(PG_arch_1, &page->flags)) {
-
-		unsigned long paddr = (unsigned long) page_address(page);
 		unsigned long phys = page_to_phys(page);
-		unsigned long tmp = TLBTEMP_BASE_1 + (addr & DCACHE_ALIAS_MASK);
-
-		__flush_invalidate_dcache_page(paddr);
+		unsigned long tmp;
 
+		tmp = TLBTEMP_BASE_1 + (phys & DCACHE_ALIAS_MASK);
+		__flush_invalidate_dcache_page_alias(tmp, phys);
+		tmp = TLBTEMP_BASE_1 + (addr & DCACHE_ALIAS_MASK);
 		__flush_invalidate_dcache_page_alias(tmp, phys);
 		__invalidate_icache_page_alias(tmp, phys);